- Added a void* argument to tiz_event_timer_init and to the corresponding
timer callback.

- Added timer event to re-schedule writes when socket is full.
Added flag in tiz_event_io_set to enable on-shot io events, instead of level
triggered, which is still the default type.

Also fixed reconnection of listeners in http renderer.
Enabled automation of http renderer unit test (fork + curl as client)
Added flag to allow manual or automated runs of the http renderer tests without
recompilation.
Fixed paths in HTTP Renderer section of tizrc.